Looks like it's under the hood, passenger side.
Check AC (Cabin) Filter Maintenance
Indicator Reset Procedure
Displayed when the A/C cabin filter life remaining is 5% or less.
When A/C filter life left is between 5% and 0% , the CHANGE
A/C FILTER SOON message will be displayed. When A/C filter life
left reaches 0% , the A/C FILTER CHANGE REQUIRED message
will be displayed.
To reset the A/C filter monitoring system to 100% after each A/C
- Press the STATUS control to access the System Check function,
the message center will display A/C FILTER XXX% RESET FOR NEW .
- Press and hold the RESET control to set to 100% , the
message center will display IF NEW FILTER HOLD RESET .
- After a successful reset, the message center will display A/C
FILTER LIFE SET TO 100% .